Tuberculosis control among high risk and vulnerable ... control among high risk.pdf ·...

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World Health Organization, Western Pacific Regional Office World Health Organization, Western Pacific Regional Office

Tuberculosis control among high risk and vulnerable populations

CPD Seminar, Ministry of Health, Fiji

10 July 2012

“The best way to predict the future is to create it”! ! !! ! ! !! ! ! !– Peter F Drucker

Nobu Nishikiori, MD, PhD, MSc Medical Officer, Stop TB WHO Western Pacific Regional Office [email protected]

World Health Organization, Western Pacific Regional Office

Tuberculosis – a social disease�

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Are we doing any better now?�

TB control in the Western Pacific Region Stop TB Special Project (2000 – 2010)

2000 2005 1999 2010

Impact targets

“50/50”

Intermediate targets 70% Case Detection

85% Treatment success 100% DOTS Coverage

TB Crisis

2015

MDG Reverse

“50/50”

Regional Plan 2000-2005



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Prevalence by Region, 1990-2015


Still too many TB patients undiagnosed

•  Case detection stagnating

•  TB concentrates among high risk populations

•  Emerging challenges

–  Migrants

–  Urban poor

–  Emerging risk factors

aging, tobacco, diabetes

–  Increasing private sector role and diverse treatment seeking

•  Low diagnostic sensitivity

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1998"1999"2000"2001"2002"2003"2004"2005"2006"2007"

Num

ber'of'm

igrant'TB'cases'

TB'Case'No4

fica4on

''(p

er'100

'000

)'

TB'among'migrants'and'local'residents,''Shanghai,'1998'B'2007'

Number"of"TB"cases"among"internal"migrants"

TB"no>fica>on"rate"among"local"residents"

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Bacteriologically'confirmed'TB'cases'iden4fied'100%''

Cases'(addi4onally)'iden4fied''by'XBray"

Sm+ve'TB'11%"

Culture'+ve''(SmBve)'TB'

49%"

Diagnostic sensitivity too low

•  Symptom screening + microscopy ! detect only 19%

•  60% of TB cases would be missed without X-ray screening

Cases'iden4fied''by'symptom'screening"

Sm+ve'TB'19%"

Culture'+ve''(SmBve)'TB'

21%"

TB'disease'prevalence'survey'Cambodia,'2002''

(Data from Draft Report National Prevalence Survey in Viet Nam 2006-7)


Need for more sensitive diagnostics

1 10 100 1000 10000 100000 1 M

CFU (colony forming unit ) per ml

More sensitive diagnogostics LED Microscopy 10,000/ml

LAMP

50-150/ml

Automatic NAAT (Xpert)�

50-150/ml

Line-probe assay

10,000/ml

Liquid culture

10-100/ml

“Smear-positive” “Smear-negative”

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Xpert™ MTB/RIF (GeneXpert)

•  TB diagnosis •  Rif resistance ! 2 hrs from sputum specimen


Actions for improved case detection

Contact'inves4ga4on'

• Children"• Household"• Workplace"

Clinical'risk'groups'

• HIV"• Smokers"

• Diabe>cs"• Previous"TB"• Malnourished"

• Drug"abusers"

Risk'popula4ons'• Prisoners"• Urban"poor"dwellers"

• Migrants"

• Workplace"(HCW)"

• Elderly"

Ac4ve'Case'Finding'(TB'Screening)'

Minimizing'physical,'financial'and'social'

barriers'

Improved'health'

communiBca4on'

Engaging'all'care'providers'

Improved'diagnos4c'

tools'

Pa>ent"pathway"

Symptoms'recognized'&'pa4ents'take'

ac4on'

Health'care'u4liza4on'

No4fica4on'

Infected'

Health services delay

Access delay

Patie

nt d

elay

Ac4ve'TB'TB'

Diagnosis'

Improved'repor4ng'system'

Regional Strategy to Stop TB in the Western Pacific (2011-2015), WHO WPRO Adapted and modified from “Action framework for higher and earlier TB case detection”, WHO

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TB high groups


TB high risk and vulnerable populations

TB high risk groups •  Increasing case

detection •  Reducing transmission

through early detection •  Mitigating institutional

amplifiers

Vulnerable and marginalized

•  Service delivery to increase access to quality care

•  Addressing health inequity

•  Expanding health system reach through TB programme

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Diabetes patients

Smokers

Migrants

Urban slum / homeless

Poor / malnourished

TB contacts

PLHIV Prisoners

Elderly

Minorities Remote areas

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TB contact investigation (CI)

•  Overall yield from a literature review (low and middle income):

–  4.5% for all TB –  ~2% for bacteriologically confirmed –  High yield among children

•  Heterogeneity among studies

•  Yield might be lower in intermediate burden settings in the Region

–  1.99% in Hong Kong (Noertjojo, Tam, et al, 2004)

–  0.93% in Singapore (Chee, et al, 2004)

–  1.14% in Singapore (index cases from correctional facilities, Chee, et al, 2004)

•  Nevertheless, in-depth yield analysis might be useful

•  LTBI treatment for close contacts esp children ! a key for


Diabetes

•  TB risk (relative to general pop) –  2-3 times higher –  Dose response :

poor control ! higher TB risk

•  Delayed sputum conversion, death during TB treatment, and relapse

Cumulative hazards for active TB by diabetic status, among a cohort of clients (>65yrs) registered with an elderly health service in Hong Kong

Leung, et al. 2008. "Diabetic control and risk of tuberculosis: a cohort study." Am J Epidemiol 167(12): 1486-1494.

HbA1c >= 7%: annual incidence 422 per 100 000

No diabetes: annual incidence 214 per 100 000

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TB-DM collaborative framework

Diabetes"clinic� TB"DOTS"clinic�

Case finding: • Intensify detection of TB among DM patients Care delivery:�• Ensure TB infection control • Ensure high quality TB treatment and management Outcome:�• Better control for DM by detecting and treating TB early

Case finding: • Screen TB patients for diabetes Care delivery: • Ensure high quality diabetes management Outcome: • Better TB cure, less relapse by controlling DM

Effective Referral and coordination

Establish"mechanisms"for"collabora>on�

(Stop TB, WHO WPRO, based on “Collaborative Framework for Care and Control of Tuberculosis and Diabetes”, WHO/IUATLD, 2011)


People living with HIV

•  TB risk (relative to general pop) –  20-30 times higher –  Progressive increase as CD4 ↓

•  HIV worsens TB treatment outcomes and increases risk of death

•  ART reduces risk of poor TB treatment outcomes

•  Intensified TB case finding in 3 I’s •  What is the current level of TB case

detection (esp systematic TB screening)?

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Tobacco smokers

•  TB risk (relative to general pop) –  Active smoking: 1.5-3 times higher –  Passive smoking also increase the risk

Current smoker: annual incidence 735 per 100 000

Ex-smoker: annual incidence 427 per 100 000

Never smoked: annual incidence 174 per 100 000

Cumulative hazards for active TB by smoking status, among a cohort of clients (>65yrs) registered with an elderly health service in Hong Kong

Leung, et al. 2004. "Smoking and tuberculosis among the elderly in Hong Kong." Am J Respir Crit Care Med 170(9): 1027-1033.


Elderly

•  Changes in population structure – rapid aging

•  A higher TB disease burden carried by older population

!  Doubled impact

•  Effective entry points? –  ? Institutions –  ? Health care package

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(Sta4s4c'of'TB,'JATA/MOHLW,'Japan)�

Increasing"propor>on"of"superUelderly"(>80y/o)"among"TB"pa>ents"

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Prison TB control

Keys to successful control: "  Political commitment "  Strong entry screening "  Early case detection with

timely and quality diagnostics "  Infection control and improved

living conditions "  Monitoring the epidemiological

situation (!) "  Monitoring DR-TB rates

"  Operational research (periodical assessment)

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1999" 2000" 2001" 2002" 2003" 2004" 2005"

Rate"per"100

"000"pop

ula>

on"

TB'burden'in'correc4onal'ins4tu4ons'in'Hong'Kong'

TB"prevalence""(TB"at"entry"and"within"3"months)"TB"incidence""(TB"beyond"3"months)"TB"no>fica>on"rate"in"general"popula>on"

Data source: Wong MY, Leung CC, Tam CM, Kam KM, Ma CH, Au KF. TB surveillance in correctional institutions in Hong Kong, 1999-2005. Int J Tuberc Lung Dis. 2008;12(1):93-98.


Migration: diverse populations, diverse issues Internal'migrants'

•  Rural'to'large'ci4es'•  Issues:'access'to'services','care'delivery'

CrossBborder'popula4on'movement'

• Mostly'economically'driven'•  Issues:'legal'issues,'highBrisk'behaviours,'health'access'and'care'delivery'

'

Floa4ng'popula4on'

•  Homelessness,'urban'slums,'mining'communi4es,'etc'

•  Issues:'access'to'services,'care'delivery'

"

Labour'immigra4on'

•  Endemic'to'less'endemic'countries'•  Issue:'importa4on'of'infec4ous'diseases,'interna4onal'referral,'access'to'services'

Migra4on'and'TB'

(Stop TB, WHO WPRO)

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Migrant TB burden in Malaysia Number and % of migrant among all TB cases, by State, 2008

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959 Sabah 355

Selangor

134 Johor

375 Kuala

Lumpur �

Myanmar�

Thailand�

Cambodia�

Viet Nam�Philippines�

Indonesia�Indonesia�

(Data source: NTP Malaysia)


Cambodian irregular migrants in Thai border area

•  Some 98,000 Cambodian migrants deported from Thailand and Malaysia to Poipet in 2010

–  20% spent > 1 month in detention centres in Thailand

•  No systematic health screening •  Many stay in the border areas while

others go back to the communities

•  A large scale joint project (WHO, NTP, IOM, border police, provincial health) to be embarked for provision of TB services

Poipet

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How TB risk factors can be used in TB control/policy?


How to use TB risks in programming (1) •  Estimating the magnitude

–  Prevalence of risk factors –  Strength of the risk on TB –  Population attributable risk

fraction (PAF)

!  Contribution of the risk factors on the TB epidemic

!  Does not necessarily mean to tackle the factor with a large PAF

Prevalence RR PAF

Smoking 28.1% 2.6 31.0%

Diabetes 9.7% 2.5 12.8%

Prisoners 0.12% 20.0 2.2%

HIV 0.014% 26.7 0.4%

Elderly 12.3% 2.0 10.9%

e.g. PAF in China

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How to use TB risks in programming (2)

•  Upstream determinants vs downstream risk factors –  e.g. addressing poverty vs targeted

service delivery for homeless –  e.g. advocate for smoking reduction vs

smoking cessation among TB patients

•  Use of risk markers for targeted service delivery –  e.g. ACF in urban slum –  e.g. ACF among homeless

•  Potential impact on TB epidemics –  e.g. targeted population likely produce

more secondary cases (urban slums, prisons, etc)

Increased risk of TB

Poverty

Homeless Urban slum

Mal-nutrition

[0,0)[0,0.5429298)[0.5429298,1.032532)[1.032532,1.637538)[1.637538,221.7128]

Standardized Incidence (all forms)

[0,0)[0,0.5429298)[0.5429298,1.032532)[1.032532,1.637538)[1.637538,221.7128]


[0,0)[0,0.5429298)[0.5429298,1.032532)[1.032532,1.637538)[1.637538,221.7128]


[0,0)[0,0.5429298)[0.5429298,1.032532)[1.032532,1.637538)[1.637538,221.7128]


Neighbourhood"factor"analysis"and""targeted"interven>ons"

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Targeted case finding approaches require specific measures to provide care

•  High risk populations requires a tailored service delivery mechanism –  e.g. Migrants / urban poor

•  highly mobile / high default and transfer •  Social and financial insecurity

–  e.g. Prisons •  High co-morbidity including HIV (what

if ARV is not available?) •  Transfer and referral system (release

screening?)

91%

37%

13%

11%

39%

0%

20%

40%

60%

80%

100%

Permanent Residents (N=5915)

Migrants (N=2423)

Treatment outcome of new smear positive TB by residence status, Beijing, 1997-2002

Transferred

Defaulted

Died

Failed

Completed

Cured

Cases among migrants

(Up to 35%)

Zhang, L.X. et al., 2006. Int J Tuberc Lung Dis, 10(9).�


Summary

•  TB control among high risk populations is a new front-line to further accelerate TB control

•  It also opens up doors for public health interventions to address health inequities

•  Identifying and prioritizing TB high risk populations require country specific epidemiological analysis, strategic decision, partnership beyond the health sector

•  WHO WPRO committed to play a vital role in facilitating the exchange

of experiences, providing guidance and catalyzing innovations

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